Low-temperature explosion process of disintegrating wood and the like



Patent ed May 25, 1926. v

UNITED STATES 1,586,159 PATENT OFFICE.

WILLIAM H. MASON, OF LAUREL, MISSISSIPPI.

Low-TEMPERATURE EXPLOSION raocnss or msmrnena'rme woon AND THE LIKE.

No Drawing. Original applicationfiled September 24, 1924, Serial No.739,748. Divided'and this application filed July 6, 1925. Serial No.41,898.

My. invention relates to a process of disintegrating ligno-cellulosematerial such as wood, for example by explosion at relatively lowtemperatures whereby charring and discoloration is avoided.

This application is adivision of my prior copending application Serial#739,748,.filed September 24, 19%.

The wood or other ligno-cellulose material,

preferably reduced to chips, is placed in a closed, high pressurechamber, having a restricted valved outlet or outlets of an area, whichis relatively restricted as compared with cross section of area ofchamber. To

secure best results, the section of the outlet should be less than ofthe section of cylinder bore.

Steam, water or other moisture supplying fluid material is introducedinto the closed 0 chamber or gun, whereby the chips are penetrated,moistened and heated. For example, hot water or steam at pressures of,say, -100 lbs. per square inch, may be advantageously made use for suchpreliminary 5 penetration and moistening steps. The tem peratures of themoisture supplying penetrating material may be considerably higher thanthis, but steam pressures and corresponding temperatures having atendency to 0 produce charring and discoloration are to be avoided, andin any event in carrying out the resent invention the steam pressureshou d not exceed 350 lbs. per square inch. When steam at 100 lbs. persquare inch is 5 used for this preliminary step, exposure of the chippedwood to the steam for a part of a minute is ordinarily sufficient, butthe steaming may be continued for a longer interval, if desired. D Afterthe chips have been subjected to penetration by hot moisture supplyingmaterial, the un is charged with compressed fluid material of sucha'nature that high pressures may be secured without the accompanyinghigh temperatures necessarily present with high pressure steam. Forexample, fluids such as compressed air, oxygen, nitrogen, and otherfixed gases, may be used. In this way, the pieces of ligno-cellulosemate- 0 rial, such as wood chips, after apreliminary heating andmoistening may be surrounded and penetrated, and their intersticesfilled with the fluid material, as compressed air, at a pressure whichis greater than 275 lbs. 5 and preferably in excess of 400 lbs. per

square inch. I have found that it is necessary to malre use of pressuresof 275 pounds per s uare inch or over, in order to produce an e ectivefibration of the wood. I have obtained very eflicient fibration withpros sures of 700-800 lbs. and higher pressures, such as 1000 lbs. persquare inch, or even higher may be made use of.

The introduction of the low-temperature, high-pressure fluid ispreferably carried out in such a manner as to avoid undue coolmg of theligno-cellulose material. The purpose of using such fluids isto obtainhigh penetrating pressures, without temperatures which would char ordiscolor the wood, and so long as such undesirable temperatures areavoided, it is not necessary and is, in fact, undesirable to produce anyconsiderable reduction oftemperature in the course of in-" troducing thelowtemperature, higl1-pressure fluid. In carrying out the operation inthis Way, the gun chamber can be brought up to pressure with less gasthan would be required were undue lowering of temperature permitted. 1

After the pressure inside and outside the pieces of wood has becomesubstantially bal-' anced, which ordinarily does not require more than afractionof a minute, the constricted outlet of the gun is opened, andthe contents are progressively discharged into a region of lower,preferably atmospheric, pressure therefrom and are reduced to a highlydivided fibrous state. The high pressure is preferably maintained in thegun so far as possible until the discharge is completed or substantiallycompleted, and when this is done the fibration of the material lastdischarged is not materially reduced, as will be the case where thepressure is not'maintained during discharge. By carrying out theoperation in the manner which I have described, the charring anddiscoloration temperatures being avoided, the fibrated product obtainedis substantially completely free from discoloration, and is well adaptedfor theproduction of high grade pulp, as for the manufacture of goodquality paper and other products.

I claim l. The process of disintegrating lignocellulose material whichconsists in introducing same into a high-pressure chamber, introducingmoist fluid in the said chamber, introducing compressed gas into saidchamber at a pressure higher'than that of the moist fluid material, anddischarging the contents of the chamber through a relatively restrictedoutlet, whereby material is disintegrated without being'subjected totemperatures which would char or discolor.

2.-The process of disintegrating lignocellulose material which consists-in introducing" same into a high-pressure chamber, introducing moistfluid 1n the said chamber, introducing compressed air into said chamberat a pressure higher than that of the moist fluid material, anddischarging the contents of the chamber through a relatively restrictedoutlet, whereby material is dlsintegrated without being subjected totemperatures which would char or discolor.

3. The process of disintegrating l 1gnocellulose material, whichconsists in introducing same into a highpressure chamber, introducingsteam into said chamber, introducing compressed air into said chamber ata pressure higher than steam pressure, and ejecting the contents of thechamber through a relatively constricted outlet opening,whereby thematerial is disintegrated to such an extent as to be immediatelyavailable for use in apparatus such as paper mill heaters and the like,and substantial discoloration is avoided. v

4:. The process of disintegrating lignocellulose material, whichconsists in introducing same into a high pressure chamber, introducingsteam into said chamber, introducing compressed air. into said chamberat a pressure higher than steam pressure, and ejecting the contents ofthe chamber through a relatively constricted outlet opening, whilemaintaining high pressure within said cham ber, whereby the material isdisintegrated to such an extent as to be immediately available for usein apparatus such as paper mill beaters and the like, and substantialdiscoloration is avoided' 5. The process of disintegratinglignocellulose material into a substantially nondiscolored product,which consists in subjecting same in a closed chamber to the action ofsteam under pressure of 350# per sq. in., subjecting same to the actionof gases at relatively low temperatures and at a pressure in excess ofsteam pressure, and progressively discharging same from said chamberthrough a relatively constricted opening.

6. The process of disintegratin ligno: cellulose material into asubstantia ly nondiscolored product, which consists in sub-.

jecting same in a closed chamber to the action of steam under pressureof 350.11: per sq. in., subjecting same to the action of gases atrelatively low temperatures and at a pressure in excess of steampressure, and progressively discharging same from said chamber through arelatively constricted opening,

- while maintaining a high pressure within said chamber.

In testimony whereof, I have signed my name hereto.

WILLIAM H. MASON.

